无传感器电流型控制开关电源斜坡补偿研究

本文首先介绍了几种常用的开关电源电流检测方法,并分析了这些电流检测方法的不足之处.在此基础上,本文重点介绍了不需要电流检测电路的无传感器电流型控制方法.通过以Boost变换器为例对无传感器电流型控制原理以及无传感器电流型控制的斜坡补偿问题进行的详细分析研究发现,对控制环路中的误差放大器输出信号提供具有适当斜率的补偿斜坡,可使系统获得更优的环路稳定性.

Research on the ramp compensation of sensorless current mode control switching DC-DC converter

Several kinds of conventional current sensing methods for switch mode power supply are firstly introduced in this paper, and the drawbacks of these current sensing methods are also analyzed. On the basis of which, sensorless current mode control method with no need of any current sensing circuit is introduced. Through detailed study and analysis on the operation principle of the sensorless current mode control and the subject on ramp compensation of the sensorless current mode control, it is found that improved stability of the control loop can be achieved by compensating a ramp with an appropriate slope to the output signal of the error amplifier. Thus, the problem of the instability of the control loop can be solved by this method.